| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [v-ing] on at the time | 8 |
|
| 2 | be go on at the time | 7 |
|
| 3 | be going on at the time | 7 |
|
| 4 | was [verb] on at the time | 5 |
|
